"I'm at a loss for words upon learning of Gary Coleman's passing,” wrote Janet Jackson, who appeared on "Diff'rent Strokes" in the early ‘80s. "I want to remember him as the fun, playful, adorable."

Actor Jamie Kennedy recalled meeting Coleman on the set of a movie he was working on at the time. "When I did 'Bowfinger', Gary Coleman was the security guard,” he said on Twitter. "A pop icon and here he was a damn security guard. He was humble and sweet. Sad."